NBC’s “Cheers” may be leaving at the end of this TV season, but the character of psychiatrist Frasier Crane is being spun off for a new comedy series to star Kelsey Grammer.That was one of the announcements NBC Entertainment topper Warren Littlefield made in a closed-door session yesterday with the network’s affiliates. Grammer’s series will be produced by Paramount Television, which also produces the long-running, award-winning “Cheers.” David Angell, Peter Casey and David Lee, who were associated with “Cheers” in previous seasons and more recently produced NBC’s “Wings,” will produce the spinoff. A second sitcom from Par is also on deck–”Mommies,” from the team of Terry Grossman, Kathy Speer and Arthur Price. Littlefield also sought to rally Peacock web affiliates worried about the net’s recent ratings woes, with late night luminaries Jay Leno and Bob Costas by his side. 90-minute ‘Tonight’? The network entertainment chief approached the web’s recent prime time ratings woes with candor, according to NBC affil sources, but pointed to a development slate as the promise of better things to come. Littlefield addressed affil concerns over the impending departure of David Letterman and said if Lorne Michaels doesn’t have a replacement ready to go by June 25, there is a possibility “The Tonight Show” would be expanded to 90 minutes. Littlefield touted the new Barry Levinson series “Homicide,” which launches after Sunday’s Super Bowl. Other projects Littlefield announced include a sitcom starring Teri Garr, being developed by Andrew Nicholls and Darrell Vickers, produced by Lorimar Television. Garr’s last TV outing was the ill-fated ABC sitcom “Good & Evil.” Positive response According to NBC affil sources, the prime time presentation generated a strong response, but affils were lukewarm on the announcement that “The Faith Daniels Show” was exiting, to be replaced by a new ayem show, hosted by Bob (“Newlywed Game”) Eubanks, dubbed “Family Fun.” “You could feel the people squirming in their seats when they announced the Eubanks project,” said Bob Grissom, VP and general manager of WETM, Elmira, N.Y.